Noise from motorbikes and scooters is a specific problem that mostly affects cities with small streets and mostly in the South of Europe. The motorbikes and scooters are badly perceived by citizens if they circulate during nighttimes, since they cause annoyance and even awakenings. Within the framework of the IMAGINE European project, some measurement campaigns were performed to gather data on the noise emitted by different types of motorbikes and scooters or mopeds, both at constant speed and during acceleration. This article presents the averaged trends of noise values recorded, as a function of speed, acceleration and vehicle type. The relationship between noise and twowheeler speed differs from that of a car, mostly because tyre noise is not relevant and because the engines run at high regimes (rpm) even at low speed. The HARMONOISE vehicle categorisation was adopted, but for scooters and mopeds more categories were used, to consider e.g., quad on one side and more common two-wheelers on the other. Data presented are useful to be put into a calculation model that considers scooters and motorbikes separately from other road vehicles, and it is mostly suitable for the HARMONOISE model for which these data were on purpose collected.